Installing Windows 7 Home Premium using the Dell Windows 7 Professional Skylake Reinstallation .iso



DellWindowsReinstallationGuide is written and maintained by Philip Yip. Scotland  , Great Britain (GB)  , United Kingdom (UK)  .



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This particular guide will take you through the necessary workarounds to install Windows 7 Home Premium (with a faded COA) on a Dell System using the Dell Windows 7 Professional Skylake Reinstallation .iso. This .iso is multi-lingual and these workarounds should work for other OEMs and other Editions of Windows. The workarounds will also work for generic Microsoft Installation .isos.

What is OEM SLP?

OEM SLP is an activation mechanism that allows major OEMs to rapidly deploy Windows without having to Manually Input 25 Digit Product Keys and make a phone call to Microsoft for every system they build.

For Windows 7 OEM SLP to work the BIOS of the motherboard contains a System License Internal Code (SLIC) of 2.1. The installation media or factory image installs a generic* Cert File (XrML Digital License) and inputs a generic* OEM SLP key. If all matches Windows 7 activates.

* Generic for each OEM and Edition of Windows e.g. every Dell model shipped with Windows 7 Professional OEM have the same generic Product Key and generic Cert File as each other.

Dell and Alienware, HP and Compaq, Lenovo and IBM, Acer, Gateway and Packard, Fujitsu, MSI, Samsung and Toshiba systems that shipped with Windows 7 preinstalled will all be activated from factory using OEM System Locked Preinstallation.

Determine Edition of Windows 7

2012-2016 Hardware (SMBIOS 2.7-2.9)

Newer systems with a Pro Edition of Windows 8.x or Windows 10 have OEM Downgrade rights to Windows 7 Pro. The hardware must be 6th Generation Intel Skylake Hardware or older for Windows 7 Driver Support. Note you may need to Slipstream USB 3.0 and Storage Controllers into your Windows Installation Media for such hardware.


Non-Pro Editions do not have a SLIC 2.1 and won’t activate Windows 7 using OEM SLP.

2009-2012 Hardware (SMBIOS 2.5-2.6)

Older systems were shipped with a COA. This is usually found in the battery compartments as it was prone to fading.

Laptop COA

If you can read it, it should state your Edition of Windows 7. You do not need your 25 digit product key for this activation mechanism.

If you cannot read the Product Key then as a rule of thumb Home Models such as the Inspiron and XPS series will ship with Windows 7 Home Premium and Business Models such as the OptiPlex, Latitude and Precision series will have  shipped with Windows 7 Professional.

Edition and EI.cfg

Windows Installation Media is normally Locked to a Specific OEM/Retail Edition but can easily be unlocked by deletion of a single file from a Bootable USB. Open up the USB in Windows Explorer:

Go to the sources folder:

Scroll down:

Look for the EI.cfg file and delete it:

Select Yes when you are warned about permanently deleting it:

Once this file is deleted you will get the option to install all the Editions of Windows 7 present on the .iso:

You should install the correct Edition of Windows 7 as determined above.

Windows Install – Skip The Product Key

During installation when you are asked for a Product Key Uncheck “Automatically Activate when I’m online” and select skip:


This will install Windows 7 without a Product Key allowing a 30 day trial.

One can check the Product ID and Activation status in system (go to Start, Right Click Computer and Select Properties). They should see that Windows 7 is not activated.

OEM Cert Collection

I have put together the OEM Cert Collection along with an associated 2 line script to install the Cert and Apply the associated OEM SLP Key. It is available as a .zip file here:

Right click the OEM SLP Major OEMs Cert and Script and extract:

Open the extracted folder and select your OEM e.g. in this case Dell:

Select your Edition of Windows in this case “Home Premium”:

And copy the OEM folder directly to the C:\ Drive:

Open the OEM folder:

Now right click the slp.cmd file and select Run as Administrator

Accept the User Account Control Prompt:

Select Ok:

Select Ok again. Note your key will differ depending on your OEM and Edition of Windows:

Press any key e.g. e to continue (this will close the command prompt):

Right Click Computer and Select Properties:

Additional Check for a SLIC 2.1

If the activation mechanism doesn’t work on your PC and you can’t locate the OEM stickers mentioned above you may not have eligible hardware for this activation mechanism. You can install a program to check whether or not you have a SLIC 2.1.

If you don’t have a SLIC Version of 2.1 you will not be able to activate Windows 7 using OEM SLP.

You can use RW-Everything to manually determine whether or not your system has a SLIC.

To determine your SLIC launch RW-Everything and select Access → ACPI Tables:


Select the SLIC Tab:


Scroll down until you get the SLIC Marker Structure. You are interested in 2 fields:

  • OEM ID
  • SLIC Version

In this case the OEM is Dell and the SLIC Version is 2.1 making the system Eligible to Activate using Dell OEM SLP.

N.B. A SLIC Version of 2.0 is eligible for Windows Vista OEM SLP only.